Join Date: Feb 2009
Location: Glendale, Arizona, USA
Model: 1987 GL1200 Interstate 290,000 miles
Perhaps a carb is draining into the combustion chamber.
I know you say the carbs are fine, but how do you know that? A very large percentage of running problems, on a GL12, are carburetor/fuel/air related. There's not much else to go wrong.
Why ain't we ridin'?